1. Field of the Invention
This invention concerns a device for thermal drying of webs, sheets, etc., of materials that are conveyed along a conveyor path over guide elements that are provided in the vicinity of dryer elements of a dryer unit.
2. The Prior Art
Known dryers that are used with modern printing machines for accelerating the drying of printing inks work with infrared heat sources for example which have radiant reflectors and baffles to guide the sheets opposite them. Such IR dryers work with IR heat sources having a working temperature of about 900.degree. C. on the glass surface of the lamp, so the dryer must then be cooled with a suitable coolant such as water containing antifreeze. Then the heat is removed from the coolant, which has been heated up in the area of the dryer, in a suitable heat exchanger. Electric power supply and control equipment or switchgear and suitable cooling equipment are necessary for the coolant. This equipment must be set up next to the machine or at a distance from it. An arrangement of control panels and cooling equipment that takes up a lot of space next to the machine is often impossible in a printing room, so then it is necessary to rely on arrangements that do not require long supply lines and coolant lines.
It is already known that residual heat and air can be vented from the area of the dryer by providing a exhaust fan at the end of the printing machine.